1. Field of the Invention
The present invention relates to an electronic musical instrument which creates a musical tone having inharmonics in by calculating harmonic functions corresponding to a fundamental wave of the musical tone.
2. Description of the Prior Art
Conventional harmonic-synthesis methods for synthesizing harmonic functions corresponding to a fundamental wave generally handle integral harmonics alone. A sine-wave synthesis method, which is one of the prior art synthesis methods, can also produce only a synthesized tone which is far from an acoustic musical tone. To create an inharmonic which is contained in the acoustic musical tone through the use of the sine-wave synthesis method, it is necessary to use oscillators in an equal in number to the harmonics desired. This, however, is almost impractical from the economical point of view. On this account, low-cost, popular versions of electronic musical instruments do not employ such a method but instead generate harmonics through the use of a nonreal time method and, as a result, produce only musically unsatisfactory tones.
Tones of the stringed instruments, which are acoustic musical instruments, contain a second harmonic having a wavelength that is one-half that of the fundamental wave which is equal to the length of the string, a third harmonic having a wavelength that is one-third that of the fundamental wave, . . . and, on top of that, a few hundredth harmonics. In addition, they have the inherent "inharmonicity" that the high order harmonics further shift toward higher frequencies as frequency rises. This makes the tones of the stringed instruments metallic or brilliant.